Amazing Circlotron with Power JFets

[Nelson Pass]

Input (gate) voltage? He said sheepishly.

I mentioned it because it's an interesting example of how
things work - the output device is actually driven by the
voltage across the resistor with current provided by the
input JFET. This voltage has been bootstrapped by the
output, so now it depends on the gain of the output
device.

So you have to ask yourself - is this really a follower?

 

[Michael Rothacher]

Thank you, Nelson. That is illuminating, as always.

As I was pondering your question last night and doing a little thought experiment, I had a weird "there is no spoon" moment. I hesitate to mention it until I've seen it for myself, but I'm going to need 2 independent wave generators. I'll report back if I may.

 

[Michael Rothacher]

I don't think that removing R7 and TH1 is a good idea given that the SJEP120R100 has a positive temperature coefficient.

Maybe so, but since I'm building this in my hypothetical laboratory, I'd try it without them first, and see what I got around a volt and a half-ish with some degeneration and big 'ol heatsinks.

Then I'd start wishin' for some high gain, higher voltage P-channel input JFETs and scale it up a notch. Then we'd have us one mean circlotron.

But that's just how I roll, dude.